Handle GitHub rate limits better?

[jimhester]

Unfortunately many of the builds are now failing with github rate limit issues.

Error in gh_process_response(raw) :
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GitHub API error (403):
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Message: You have exceeded a secondary rate limit. Please wait a few minutes before you try again.
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Read more at https://docs.github.com/en/free-pro-team@latest/rest/overview/resources-in-the-rest-api#secondary-rate-limits
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Calls: local ... <Anonymous> -> gh_process_response -> gh_error -> throw

Maybe there are alternative queries we could run to avoid this?